Love, it’s in your genes

Most kids worry about passing tests, winning games, lost phones, fractured bones—and whether or not they will ever really fall in love. While the first few things are of relatively low value in the scientific pursuit, three Chinese researchers have focused on that last question. All in a bid to find out some of the more interesting questions about our genes: Why do some students stay single? What factors determine if a young adult falls in love?

Beyond the familiar factors—hair style, beauty, clothes, smooth talking and engaging personality—they set out to show that genetic variants may contribute to the start or non-start of a romantic relationship.

“Love-related behaviors, such as pair bonding and affective affiliation, are shown to be associated with the serotonin levels in the brain,” they said.

Is it possible that the 5-HT1A gene polymorphism is related to the likelihood of a young adult being in a relationship? To explore answers they tested 579 Chinese undergraduate students. Hair follicle cells were collected for genotyping. They said that genomic DNA was extracted from hair follicle cells by using the Chelex-100 method. -C1019G in 5-HT1A was amplified by polymerase chain reaction.

The results: Individuals carrying the G allele (CG/GG) of C-1019G polymorphism were more likely to be single than CC carriers.

This is consistent with the finding that G allele carriers are less comfortable in close relationships with others. Indeed, G allele carriers are more likely to develop neurotic personalities and psychiatric disorders such as major depression and borderline personality disorder. As pessimism and neuroticism are detrimental to the formation, quality, and stability of relationships, this connection between G allele and psychological disorders might decrease carriers’ dating opportunities or lead to romantic relationship failure.

“Tests on 579 Han Chinese students revealed that half of those who inherited two copies of the C variant – one from each parent – were in relationships. But students who carried one or two copies of the G variant had only a 40 percent chance of being in a relationship. The effect was small, but statistically significant.”

“Our results demonstrate the importance of 5-HT1A C-1019G in individual differences on romantic relationship formation, thereby providing evidence for the genetic contribution to complex social relationships in certain contexts.”

While it may not explain everything, it does help show that our genes control more than just our eye color, which we already knew, but proof is always welcome no matter how odd ball. Sure it may not cure cancer, but it’s another piece of the gene puzzle, and oh what a puzzle it is.

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One response

Lovely article. I’m concerned that people are focusing too much on 5-HT in behavioural studies, but at least the results speak for themselves. According to the study, only 1.4% of the variance in the log odds could be explained by the polymorphism.

I’m also surprised that the study authors didn’t control for something more intuitively connected with whether or not a university student is in a relationship, such as participation in some extracurricular organization. I’m not familiar with higher education in China, but presumably they still have such things; and if I’ve learned anything from going to university, it’s that being sociable in that way increases your chances of meeting somebody.